1. Field of the Invention
The present invention relates to a cellular telephone set, a dial lock releasing method to be used in the same, and a program therefor. More particularly, the invention relates to a method for releasing dial lock for disabling key input in the cellular telephone set.
2. Description of the Related Art
Conventionally, in the cellular telephone set, there is provided a dial lock function for disabling key input except for entry of a personal identification number (terminal identification number) so as to prevent unauthorized use by others as stolen or lost by unconsciously leaving or to avoid erroneous key input as stored in a bag and so forth, as disclosed in “dial lock for preventing malfunction”, NTT Docomo (registered trademark) Mova(registered trademark) N504i Instruction Manual, Chapter of Basic, pages 252 to 255, April, 2002.
In such cellular telephone set, the dial lock function becomes active by depressing a preliminarily set combination of keys or by selecting item of the dial lock function among an operation menu or setting menu to instantly disable key input except for entry of the identification number. Namely, in the conventional cellular telephone, by inputting the identification number under a condition where key input is disabled, dial lock function becomes null (released) to enable key input.
In addition to releasing of the dial lock function, the identification number may be used for setting various functions of the cellular telephone set, such as “changing of terminal identification number”, “setting of telephone number”. “setting of inhibited operation”, “setting into secret mode”, “setting into secret only mode”, “setting operation in response to number not notifying call”, “resetting of setting”, “setting of telephone directory designation”, “setting of calling destination”, “setting of mail security”, “setting of history display” and so forth, as disclosed in “About Identification Number”, NTT Docomo (registered trademark), Mova(registered trademark) N504i Instruction Manual, Chapter of Basic, pages 248 to 249, April, 2002.
In the foregoing conventional cellular telephone set, dial lock function is installed for preventing unauthorized use as lost or malfunction as stored, the identification number is used for releasing the dial lock function.
However, only one identification number can be used in one terminal, if parent buys the cellular telephone set for their child and manages the identification number, and dial lock function becomes active unintentionally, the child may not release dial lock function.
On the other hand, when the child manages the identification number, while the child may use all of the functions provided for the cellular telephone set, it becomes impossible to prevent increasing of frequency of accessing of payable contents on the internet and/or using of electronic mails and thus increasing of charge due to expansion of communication period and so forth. Therefore, the parent may not control the charge for the cellular telephone set.